Best Harvesting Windows
Best Harvesting Windows
Milford, CT (Summer Example)
Harvest Start Time
Graph illustrates predicted bacteria doublings for Vibrio parahaemolyticus bacteria in harvested oysters under
3 cooling strategies. These predictions are based on the established relationship between temperature and bacterial growth,
using NWS NDFD air temperature forecasts for selected harvest start times. Levels of Vp bacteria in the oysters begin to increase rapidly once oysters are removed from the water at the time of harvest. The more rapidly oysters are cooled to an internal temperature of 50°F,
the fewer times the bacteria are able to double. More rapid cooling results in lower Vp levels in the oysters,
and reduces the risk of illness associated with oyster consumption.
This tool is intended to assist oyster producers in choosing an appropriate cooling method and optimal start time of harvest, in order to achieve the lowest number of bacterial doublings when using a given cooling strategy.
Post-Harvest Cooling Strategies:
- Rapid cooling (blue line): Oysters placed into Ice Slurry on vessel within 0.5 hours of harvest start time; oysters are cooled to an internal temperature of 50°F within 1 hour of harvest.
- Immediate on-board refrigeration (green line): Oysters are placed into mechanical refrigeration unit on vessel within 0.5 hours of harvest time; oysters are cooled to 50°F within 5 hours of being placed under refrigeration.
- 5 hours to refrigeration (red line): Oysters are exposed to air temperature on the deck of the vessel for 5 hours and placed into mechanical refrigeration on shore; oysters are cooled to 50°F within 5 hours of being placed under refrigeration.